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| author | Nate Diller <nate.diller@gmail.com> | 2007-05-09 02:35:07 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@woody.linux-foundation.org> | 2007-05-09 12:30:55 -0700 |
| commit | 01f2705daf5a36208e69d7cf95db9c330f843af6 (patch) | |
| tree | 2d2c7a042c2466ed985f6e0950450c099f02725f /fs/mpage.c | |
| parent | 38a23e311b6cd389b9d8af2ea6c28c8cffbe581c (diff) | |
| download | lwn-01f2705daf5a36208e69d7cf95db9c330f843af6.tar.gz lwn-01f2705daf5a36208e69d7cf95db9c330f843af6.zip | |
fs: convert core functions to zero_user_page
It's very common for file systems to need to zero part or all of a page,
the simplist way is just to use kmap_atomic() and memset(). There's
actually a library function in include/linux/highmem.h that does exactly
that, but it's confusingly named memclear_highpage_flush(), which is
descriptive of *how* it does the work rather than what the *purpose* is.
So this patchset renames the function to zero_user_page(), and calls it
from the various places that currently open code it.
This first patch introduces the new function call, and converts all the
core kernel callsites, both the open-coded ones and the old
memclear_highpage_flush() ones. Following this patch is a series of
conversions for each file system individually, per AKPM, and finally a
patch deprecating the old call. The diffstat below shows the entire
patchset.
[akpm@linux-foundation.org: fix a few things]
Signed-off-by: Nate Diller <nate.diller@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'fs/mpage.c')
| -rw-r--r-- | fs/mpage.c | 15 |
1 files changed, 5 insertions, 10 deletions
diff --git a/fs/mpage.c b/fs/mpage.c index fa2441f57b41..0fb914fc2ee0 100644 --- a/fs/mpage.c +++ b/fs/mpage.c @@ -284,11 +284,9 @@ do_mpage_readpage(struct bio *bio, struct page *page, unsigned nr_pages, } if (first_hole != blocks_per_page) { - char *kaddr = kmap_atomic(page, KM_USER0); - memset(kaddr + (first_hole << blkbits), 0, - PAGE_CACHE_SIZE - (first_hole << blkbits)); - flush_dcache_page(page); - kunmap_atomic(kaddr, KM_USER0); + zero_user_page(page, first_hole << blkbits, + PAGE_CACHE_SIZE - (first_hole << blkbits), + KM_USER0); if (first_hole == 0) { SetPageUptodate(page); unlock_page(page); @@ -576,14 +574,11 @@ page_is_mapped: * written out to the file." */ unsigned offset = i_size & (PAGE_CACHE_SIZE - 1); - char *kaddr; if (page->index > end_index || !offset) goto confused; - kaddr = kmap_atomic(page, KM_USER0); - memset(kaddr + offset, 0, PAGE_CACHE_SIZE - offset); - flush_dcache_page(page); - kunmap_atomic(kaddr, KM_USER0); + zero_user_page(page, offset, PAGE_CACHE_SIZE - offset, + KM_USER0); } /* |